RESUMO
BACKGROUND: Breast cancer (BC) has a complex and heterogeneous etiology, and the emergence of resistance to conventional chemo-and radiotherapy results in unsatisfactory outcomes during BC treatment. Targeted nanomedicines have tremendous therapeutic potential in BC treatment over their free drug counterparts. OBJECTIVE: Hence, this study aimed to evaluate the newly fabricated pH-sensitive multifunctional FAHA- Amygdalin@Fe2O3 nano-core-shell composite (AF nanocomposite) and/or γ-radiation for effective localized BC therapy. METHODS: The physicochemical properties of nanoparticles were examined, including stability, selectivity, responsive release to pH, cellular uptake, and anticancer efficacy. MCF-7 and MDA-MB-231 cells were treated with AF at the determined IC50 doses and/or exposed to γ-irradiation (RT) or were kept untreated as controls. The antitumor efficacy of AF was proposed via assessing anti-proliferative effects, cell cycle distribution, apoptosis, and determination of the oncogenic effectors. RESULTS: In a bio-relevant medium, AF nanoparticles demonstrated extended-release characteristics that were amenable to acidic pH and showed apparent selectivity towards BC cells. The bioassays revealed that the HA and FA-functionalized AF markedly hindered cancer cell growth and enhanced radiotherapy (RT) through inducing cell cycle arrest (pre-G1 and G2/M) and increasing apoptosis, as well as reducing the tumorigenicity of BCs by inhibiting Silent information regulation factor 1 (SIRT1) and restoring p53 expression, deactivating the Yes-associated protein (YAP)/ Transcriptional coactivator with PDZ-binding motif (TAZ) signaling axis, and interfering with the tumor growth factor- ß(TGF- ß)/SMAD3 and HIF-1α/VEGF signaling hub while up-regulating SMAD7 protein expression. CONCLUSION: Collectively, the novel AF alone or prior RT abrogated BC tumorigenicity.